Fabits MCP Server

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the action is verification but doesn't explain what happens upon success/failure, authentication requirements, rate limits, or side effects. This leaves critical behavioral traits unspecified for a security-related tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is extremely concise with a single, front-loaded sentence that directly states the tool's purpose. There is no wasted verbiage or unnecessary structure, making it efficient for quick comprehension.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the complexity of OTP verification (a security-sensitive operation), no annotations, and no output schema, the description is insufficient. It lacks details on behavior, error handling, and integration with sibling tools, failing to provide a complete context for safe and effective use.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema fully documents the three required parameters (user_id, phone_number, otp). The description adds no additional parameter semantics beyond what's in the schema, meeting the baseline for high coverage but not enhancing understanding.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description 'Verify transactional OTP' states the action (verify) and resource (transactional OTP), making the basic purpose clear. However, it doesn't specify what 'transactional OTP' means in this context or distinguish it from the sibling tool 'fabits_verify_otp', leaving some ambiguity about scope and differentiation.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance is provided on when to use this tool versus alternatives like 'fabits_verify_otp' or 'fabits_request_otp'. The description lacks context about prerequisites (e.g., after sending an OTP) or typical workflows, offering no usage instructions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.